INFLUENCE OF THE SYNCHRONIZATION TREATMENT ON THE SUPEROVULATORY RESPONSE OF MURCIANA GOATS

This study was undertaken to determine if the synchronization treatmen t that accompanies superovulation in goats affected the ovulatory resp onse and the incidence of premature regressive corpora lutea. Twenty e ight Murciana goats were submitted, once in autumn and once in spring, to one of three different synchronization regimens based on fluoroges tone acetate (FGA) sponges: treatment A, the standard short synchroniz ation system; treatment B, the standard long synchronization system an d treatment C, similar to treatment B, but with prostaglandin F-2 alph a injected two days before pessary removal. All animals were superovul ated with 16 mg of follicle stimulating hormone (FSH). No difference i n the percentage of animals with regressed corpora lutea was found due to season (27% in fall vs, 44% in spring, P = 0.196), due to the leng th of FGA treatment (41% with treatment A vs. 31% in treatment C, P = 0.55), or due to the effect of prostaglandin F-2 alpha administration (33% in treatment B vs. 31% in treatment C, P = 0.89). The number of c orpora lutea present at the time of embryo recovery did not differ amo ng treatments (P > 0.05) or seasons (P > 0.05), but embryo recovery wa s lower (P < 0.001) in animals with regressed corpora lutea (1.2 +/- 0 .6) than in animals with apparently normal luteal structures (8.9 +/- 0.9), These data show that the synchronization regimen does not interf ere with the superovulatory response and that high percentages of prem ature luteal regression can be associated with FSH-based superovulator y regimes. In the same way, it can be concluded that the administratio n of prostaglandin F-2 alpha does not increase the number of animals s howing premature luteal regression.